A pattern reconfigurable antenna refers to an antenna whose antenna directivity pattern is changed by changing current distribution in an antenna unit.
In a communications system, a pattern reconfigurable antenna may be configured on both a base station and user equipment (UE). The pattern reconfigurable antenna configured on the base station may support omnidirectional directions and M different directional directions (M≥1), and the pattern reconfigurable antenna configured on the UE may support N different directional directions (N≥1). The omnidirectional directions indicate that a directivity pattern has basically same performance in all directions on a horizontal plane or a vertical plane, and antenna gains are basically the same in all angles on the horizontal plane or the vertical plane, that is, an antenna is not directional. The directional direction indicates that a directivity pattern has strong power in some space angles but has weak power in some other space angles, that is, an antenna is directional.
If the pattern reconfigurable antenna is configured on both the base station and the UE, the directional directions of the base station and the directional directions of the UE have M×N combination manners. An optimal combination manner may be determined by using an exhaustive attack method. However, complexity of the exhaustive attack method is O(M×N), and the complexity is relatively high.